B. Copper Overload and Wilson's Disease 8
Wilson's disease results from a genetically inherited metabolic defect in which
copper can no longer be tolerated at normal levels. The clinical manifestations
are liver disease, neurological damage, and brown or green (Kayser-Fleischer)
rings in the cornea of the eyes. Patients suffering from Wilson's disease have
low levels of the copper-storage protein ceruloplasmin; the gene and gene products
responsible for the altered metabolism have not yet been identified. Chelation
therapy, using K2Ca(EDTA), the Ca2 + ion being added to replenish body
calcium stores depleted by EDTA coordination, 2,3-dimercaptopropan-I-ol (BAL,
British Anti-Lewisite), or d-penicillamine to remove excess copper, causes the
symptoms to disappear. The sulfhydryl groups of the latter two compounds
presumably effect removal of copper as Cu(I) thiolate complexes. Wilson's disease
offers an excellent opportunity for modem methodologies to isolate and
clone the gene responsible for this altered Cu metabolism, ultimately providing
a rational basis for treatment.